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Abstract：
To achieve high-efficiency nutrient removal in constructed wetlands (CWs), a novel simultaneous nitrogen and phosphorus removal (SNPR) process was developed by combining nitrification, endogenous denitrification, and denitrifying phosphorus removal. In SNPR process, denitrifying glycogen-accumulating organisms (DGAOs) and denitrifying polyphosphate-accumulating organisms (DPAOs) utilized NOx--N(NO3--N or NO2--N) as electron acceptor and poly-beta-hydroxy-alkanoates (PHAs) as carbon sources for endogenous denitrification and denitrifying phosphorus removal processes. Results from 217 days of operation showed that a high-level of nitrogen removal efficiency of 83.73% was achieved with influent COD/N of 4. The success was attributed to the fact that most of influent carbon sources could be transformed into PHAs before nitrification via enriching DGAOs and DPAOs in CW, which simultaneously improved nitrification and denitrification due to reducing oxygen and carbon sources consumption by aerobic heterotrophs. Phosphorus was mainly removed via denitrifying phosphorus removal, and PO43--P removal efficiency reached up to 87.84% with even common gravel used as substrate. Stoichiometry analysis revealed that DGAOs were the main organisms providing nitrite to DPAOs, suggesting that the effective PO43--P removal under high DGAO abundance condition might be attributed to the coordination of DGAOs and DPAOs in SNRP processes.
摘要：
为了在人工湿地（CWs）中实现高效的养分去除，通过结合硝化，开发了一种新型的同步脱氮除磷（SNPR）工艺，内源性反硝化，和反硝化除磷。在SNPR过程中，反硝化糖原积累生物（DGAOs）和反硝化多磷酸盐积累生物（DPAOs）利用NOx-N（NO3--N或NO2--N）作为电子受体，聚β-羟基链烷酸酯（PHAs）作为碳源用于内源性反硝化和反硝化除磷过程。运行217天的结果表明，进水COD/N为4时，达到了83.73％的高脱氮效率。成功归因于以下事实：通过在CW中富集DGAO和DPAO，大多数进水碳源可以在硝化之前转化为PHA，由于好氧异养生物减少了氧气和碳源的消耗，同时改善了硝化和反硝化。磷的去除主要是通过反硝化除磷，即使使用普通砾石作为基质，PO43--P的去除率也高达87.84％。化学计量学分析表明，DGAOs是向DPAOs提供亚硝酸盐的主要生物，表明在高DGAO丰度条件下有效去除PO43--P可能归因于SNRP过程中DGAO和DPAO的协调。
